A known seat slide apparatus for a vehicle is disclosed, for example, in JP2009-62006A which will be hereinafter referred to as Reference 1. Specifically, as illustrated in FIGS. 27A, 27B, and 27C, the seat slide apparatus disclosed in Reference 1 includes a lower rail 201, an upper rail 202 connected to the lower rail 201 so as to be relatively movable thereto, and a lock lever 203 selectively locking or restricting the relative movement of the upper rail 202 relative to the lower rail 201. The seat slide apparatus also includes a control lever 210 and a cancel lever 220 each of which is connected to the upper rail 202 to be rotatable thereto.
As illustrated in FIGS. 28A, 28B, and 28C, in a case where a cable 205 is pulled in association with a forward folding of a seatback of a seat at which the seat slide apparatus is provided and the control lever 210 is rotated, a lock lever contact portion 211 of the control lever 210 pushes or presses a control lever contact portion 204 of the lock lever 203. As a result, the locking (restriction) of the relative movement of the upper rail 202 relative to the lower rail 201 is released (i.e., a released state of the locking). That is, in a state where the seatback is folded forward (i.e., the seatback is in a forward folded state), the released state of the locking of the relative movement of the upper rail 202 relative to the lower rail 201 is maintained.
At this time, a second cancel lever contact portion 212 of the control lever 210 is separated from a second control lever contact portion 221 of the cancel lever 220 that is biased to rotate. Thus, a memory plate contact portion 222 of the cancel lever 220 makes contact with an upper surface of a memory plate 206 provided at the lower rail 201.
Afterwards, in a case where the upper rail 202 moves relative to the lower rail 201 in one direction, i.e., in a leftward direction in FIG. 28B, the cancel lever 220 is separated from the memory plate 206 to thereby further rotate until a first control lever contact portion 223 of the cancel lever 220 makes contact with a first cancel lever contact portion 213 of the control lever 210. At this time, an end portion, specifically, a lower end portion, of the memory plate contact portion 222 of the cancel lever 220 is positioned lower than an end portion, specifically, an upper end portion, of the memory plate 206.
Accordingly, in a case where the upper rail 202 that moves relative to the lower rail 201 in the aforementioned one direction changes the moving direction to an opposite direction, the cancel lever 220 rotates in a state where the memory plate contact portion 222 climbs up or override the memory plate 206. Then, the first control lever contact portion 223 of the cancel lever 220 is separated from the first cancel lever contact portion 213 of the control lever 210. In the aforementioned state, in a case where the seatback is pulled back to release the forward folded state, the control lever 210 returns to rotate so that the lock lever contact portion 211 of the control lever 210 is separated from the control lever contact portion 204 of the lock lever 203. As a result, the relative movement of the upper rail 202 relative to the lower rail 201 is locked or restricted. That is, the lower rail 201 and the upper rail 202 return to a relative position which will be hereinafter also referred to as a neutral position at which the end portion of the memory plate contact portion 222 matches the end portion of the memory plate 206.
According to the seat slide apparatus disclosed in Reference 1, on the assumption that the upper rail 202 moves in the opposite direction until the cancel lever 220 that is in separation from the memory plate 206 returns to the position that matches the position of the memory plate 206, i.e., on the assumption that the upper rail 202 returns to the neutral position, the control lever 210 (specifically, the first cancel lever contact portion 213) is released from the cancel lever 220 (specifically, the first control lever contact portion 223) so that the cancel lever 220 is brought to be rotatable.
Specifically, in a case where the seatback is pulled back to release the forward folded state while the cancel lever 220 is being in separation from the memory plate 206, the control lever 210 is inhibited from rotating, so that the lock lever contact portion 211 of the control lever 210 keeps pressing down the control lever contact portion 204 of the lock lever 203. Thus, the released state of the locking of the relative movement of the upper rail 202 relative to the lower rail 201 is maintained. As a result, even in a case where the relative movement of the upper rail 202 relative to the lower rail 201 is not locked by the lock lever 203, the seatback is brought to a state so that an occupant may be seated in the seat, which may lead to deterioration in operability of the seat slide apparatus.
A need thus exists for a seat slide apparatus for a vehicle which is not susceptible to the drawback mentioned above.